Removed --double command line parameter.
Atlanteans have cornflour, not 'regular' flour
No capital letters in the middle of sentences
Buildings are enhanced, not expanded
- Removed Tribe_Descr::world().
- Removed lots of unused arguments in production_program.(h|cc) and reordered some of
  them to put output parameters last.
A couple of string fixes by hjd. Discovered while translating
Removed some unneeded ::Index typedefs.
Refactored handling of Objectives to not use a custom container anymore.
Remove dead code in objectives menu.
Intermediate commit
Finished fixing all uses of operator bool.
Remove Building_Index and Ware_Index. 

These were only boxed integer types (for typesafety). While the idea is neat,
they do not work out great. A lot of weird casting is needed and operator bool
is really confusing if you just think of them as integers.

As long as opaque_typedefs are not part of the language, we should not use
boxing. There is some library support in boost/strong_typedef.hpp, but their
original author even does not use them anymore, so we should probably not too.

tl;dr: Do not box POD in Widelands source base for now.
Fixed bug in loading of objectives.
Removed wl_erase.
Removed wl_index_range.
Replaced BOOST_FOREACH with c++11 container styled loops.
Remove --double commandline option.